Method for predicting hydration damage degree of shale

A damage degree and shale technology, applied in the field of predicting the strength of shale damaged by hydration, can solve the problems of shale mechanical strength damage, shale softening, aggravating the difficulty of effective support for deep shale, etc., to achieve rapid prediction and improve work efficiency. The effect of efficiency

Active Publication Date: 2019-04-16
CHINA PETROLEUM & CHEM CORP +2
View PDF5 Cites 17 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The water entering the formation will damage the mechanical strength of the shale, making the shale soft, resulting in the closure of self-supporting fractures and the embedding of proppant, which further exacerbates the problem that deep sh

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for predicting hydration damage degree of shale
  • Method for predicting hydration damage degree of shale
  • Method for predicting hydration damage degree of shale

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] figure 1 A flow chart of a method for predicting the strength of hydration-damaged shale is provided for an embodiment of the present invention, such as figure 1 As shown, the method of this embodiment includes the following steps:

[0044] S1: Prepare standard rock samples of the target shale block: prepare N standard rock samples of the target shale block, select one of the standard rock samples without soaking, and the soaking time of the other N-1 standard rock samples is t respectively 1 , t 2 ...t n-1 Specifically, considering the influence of shale anisotropy on rock strength and deformation, the standard rock samples of the target shale block are prepared in the same direction, and water is avoided during the standard rock sample processing, and the standard rock samples are not used in the test. before hydration. Specifically, the soaking device is shown in the accompanying drawings in the description figure 2 As shown, the soaking device includes a proce...

Embodiment 2

[0063] Taking a shale block as an example below, the implementation method of the present invention is further described in detail, as follows:

[0064] According to step S1, five standard rock samples of the target shale block are prepared, one standard rock sample is not soaked in water, and the remaining four standard rock samples are soaked in water for 3 days, 5 days, 10 days and 20 days respectively. .

[0065] According to step S2, the closed pressure of the block is 70MPa, after drying the soaked standard rock samples, triaxial mechanical test is carried out under the confining pressure of 70MPa to obtain the rock elastic modulus E of each standard rock sample n , Poisson's ratio v n , the internal friction angle The measurement results are shown in Table 1.

[0066] Table 1 Triaxial mechanical test parameter table

[0067]

[0068] According to step S3, the Poisson's ratio-water immersion time curve is obtained by using the results of the triaxial rock mechani...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Compressive strengthaaaaaaaaaa
Compressive strengthaaaaaaaaaa
Login to view more

Abstract

The invention discloses a method for predicting the hydration damage degree of shale. The method includes the following steps that: S1, target shale block standard rock samples are prepared, and are subjected to soaking treatment; S2, after being dried, the standard rock samples are subjected to a triaxial mechanics experiment; S3, on the basis of the results of the triaxial mechanics experiments,the Poisson's ratio-water immersion time curve and elastic modulus-water immersion time curve of the standard rock samples are obtained; S4, the internal friction angles of the standard rock samplesare determined according to the Mohr-Coulomb strength theory, and a relational expression of the internal friction angles and immersion time is obtained; S5, post-water immersion Weibull distributionparameter m is obtained through the softening constitutive model of Weibull distribution under water immersion, and the rock compressive strength F0 of the shale which has been damaged by hydration isobtained; and S6, the hydration damage degree of the shale is calculated. With the method adopted, the influence of hydration damage on shale rock mechanical parameters under different confining pressure and hydration time conditions can be quantitatively expressed, and therefore, the hydration damage degree can be quantitatively predicted.

Description

technical field [0001] The invention relates to the technical field of unconventional oil and gas exploration and development, in particular to a method for predicting the strength of hydration-damaged shale. Background technique [0002] Shale gas refers to unconventional natural gas that occurs in organic-rich shale-based reservoir rock series. It is a continuously generated biochemical gas, thermogenic gas or a mixture of the two. In cracks and pores, it exists on the surface of kerogen and clay particles in an adsorbed state, and a very small amount is stored in kerogen and asphaltene in a dissolved state. The proportion of free gas is generally 20% to 85%. [0003] Deep shale gas resources buried deeper than 3500 m in my country are abundant, accounting for more than 60% of shale gas resources, and have good development prospects. It is easy to close under closing pressure, which is an important reason for the poor fracturing effect. [0004] At present, hydraulic frac...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N3/12G01N1/28G01N1/30
CPCG01N1/28G01N1/30G01N3/12G01N2203/0256
Inventor 郭建春李远照廖如刚赵志红高东伟张驰李婷张晗苏慕博文李鹏毕文韬崔静
Owner CHINA PETROLEUM & CHEM CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap